Electric switch



May 1958 E. A. KATHE 2,836,675

ELECTRIC SWITCH Filed Sept. 28, 1955 2 Sheets-Sheet 1 IN V EN TOR.

,fimm' Kathe A TTORNE YS 1953 E. A. KATHE 2,836,675

ELECTRIC SWITCH Filed Sept. 28, 1955 2 Sheets-sheaf 2 II'I IN V EN T OR.,Zmu/nd KM! A TTORNE YS United States Patent ELECTRIC SWITCH Edmund A.Kathe, Columbus, Ohio Application September 28, 1955, Serial No. 537,125

4 Claims. (Cl. 200--87) therebetween.

Another object of the invention is to provide in an improved switchstructure movably associated circuitcontrolling elements which are movedfrom one position to another without engagement therebetween which substantially eliminates fatigue or wearing of the elements.

Another object of the invention is to provide in a switch ofthe abovecharacter a circuit-controlling element which is movable between openand closed positions by its magnetic activity in response to magneticactivity induced by an actuatable element.

Another object of the invention is to provide a circuitcontrollingswitch element and an actuatable element, each of said elements havingmagnetic characteristics and which are arranged to respond in theirmovements according to the magnetic force produced therebetween.

A further object of the invention is to provide a circuitcontrollingswitch element and an actuatable switch element, each of which arepermanently magnetized and arranged so that automatically producedmotions will be carried out by the, directed influence of themagnetizedelements to respond to induced movement therebetween.

A still further object of the invention is to provide an improved switchconstruction wherein fatigue or disruptive wearing of the parts thereofis reduced to a minimum;

the parts are formed of relatively sturdy long-wearing structures, andcombined in an advantageously compact relation of operation.

' Other objects and advantages of the invention willbe come moreapparent during the course of the following description, when read inconnection with the accompanying drawings.

in the drawings, wherein like numerals are employed to designate likeparts throughout the same:

Fig. l is a top view of an electric switch constructed in accordancewith one embodiment of the invention;

Fig. 2 is a side elevational view of the switch;

Fig. 3 is a vertical transverse section of the switch taken on line 3-3of Fig. 2;

Fig. 4 is a similar transverse sectional view taken on line 4-4 of Fig.2; i

Fig. 5 is also a transverse sectional view taken on line 55 of Fig. 2;

Fig. 6 is a transverse sectional view of the switch when adapted toalternately control two circuits; I

Fig. 7 is a front elevational view of a modified form of an electricalswitch;

Fig. 8 is a longitudinal vertical sectional view taken on line 8-8 ofFig. 7;

Fig. 9 is a transverse vertical sectional view taken on line 9--9 ofFig. 8; v

Fig. 10 is a view similar to Fig. 9 wherein certain of the switch partshave been moved; and

Fig. 11 is an exploded perspective view of certain of the switch parts.

Referring now to Figs. 1 to 6 inclusive, there is shown an electricswitch constructed in accordance with one embodiment of my invention anddesignated in its entirety by the numeral 15. This particular switch isadapted to be operated for the instantaneous opening and/or closing ofan electric circuit and is of the general variety known in the art aslimit switches. These switches are commonly employed at one or moresteps in an operation to institute the function of a component part of amachine; to stop the travel of a machine part in one direction or toreverse the travel, and to start the operation of a second machine partwhen a first associated part has reached a predetermined phase of itsindividual cycle of work. For these purposes, the switches are adaptedto be momentarily engaged and thereby establish a circuit or by theirmomentarily active condition interrupt a circuit and then allow thecircuit controls to resume a closed condition. It is highly desirabletherefore that switches of this character he of relatively simpleoperation and few well-constructed parts in order that they will performrepeatedly for long periods of time and with no more than infrequentinspections during their service.

Accordingly, I have provided a switch wherein the actuated parts respondin their movements to one another without actual contact being madetherebetween and without the inclusion of spring members which aresusceptible to fatigue or complete breakage. Thus the switch 15comprises a pair of aligned members which are initially magnetized andthen positioned relative to one another so that the magnetic propertiesof one will repel the like properties of the other. This phenomena ofmagnetic force is of course well-known and often defined as therepulsion of like magnetic poles.

The operable elements of switch 15 are supported by and contained withinan open-sided box 16. This box may be formed of any suitably moldableinsulation material such as thermo-setting plastics, resins or likematerials. As herein shown, the box has a rear wall 17 and a forwardlydirected flange or continuous wall 18 having a top wall 19, bottom wall20 and end walls 21. For this convenient mounting of the switch, the endWalls may have formed therein through holes 22 that are disposed inaligned relation to therear wall 17 and in the opposite end cornersthereof. Also the end walls 21 may have anchored therein threadedsleeves 23 that are arranged at substantially right angles to the holes22. As shown in Figs. 1 and 3, the switch may thus be mounted on avertically disposed (as shown) support panel 24 by screws 25 or on ahorizontally disposed panel according to its intended mode of engagementby a functional machine part such as a lug or boss 26 indicated inphantom line in Fig.2.

The operable parts of the switch 15 are contained within the chamberedarea 27 of the box 16 and comprise an actuating member 28 and a switchmember 29. As shown particularly in Figs. 3 and 5 in conjunction withFig. 2, the actuating member 28 is swingably mounted on an especiallyformed fulcrum pin 30 which has an annular shank 31 on which the body ofthe member 28 is pivotally received, an enlarged flange 32 abutting theinner surface of rear wall 17 and a second shank 33 that is anchored orotherwise fixedly secured in the said rear wall and Patented May 27,1958 Q. medially between the top and bottom walls 19 and 20 of the box.Preferably also the fulcrum pin 39 is located in the rear wall 17 inclose proximity to the adjacent end wall 21.

In like manner, the switch member 29 is pivotally mounted on a fulcrumpin 34 adjacent the opposite end wall 21. As shown in Fig. 3, this pinis a duplicate of pin for simplicity of manufacture, but is providedwith an outwardly-directed, axial tapped hole 35. The members 28 and 29are thus pivotally mounted at their remotely disposed ends and so as topresent their opposed ends in close proximity to one another. Now if themembers 23 and 29 are of a paramagnetic material-that is to say of aniron or steel that will substantially permanently retain a magneticforce-and their like poles are arranged in this juxtaposition, theswinging movement of one or the actuating member 28 will repel the otheror member 29 and cause it to swing in the opposite direction.

The member 28 is biased in an idle position by means of a light coilspring 36 that is received at one end in a socket 37 formed in the topwall 19. Oppositely disposed with respect to the spring 36 there is avertically disposed plunger 38 slidably mounted in the wall 20 and incontinual engagement with the member 28. As indicated in Fig. 2, whenthe lug 26 engages the outwardly disposed end of plunger 33 and thruststhe same inwardly of the box 16, the member 28 will be swung to aposition, such as is indicated by the phantom lines a. This will ofcourse produce magnetic repulsion between members 28 and 29 andconsequently motion of the member 29 to a position substantially asindicated by the phantom lines 12.

According to the switch construction shown in Figs. 2 and 4, the member29 is adapted to maintain a closed circuit condition and will be causedto instantaneously, though momentarily, open the same when swung fromits full line position to the position indicated at b. For this purpose,the member 29 which comprises a block of suitable magnetized metal hasafiixed to its upper and lower surfaces strips 40 and d1 of non-ferrousand conducting metal such as copper or the like. In Fig. 3, it will beseen that either strip 46 or 41 is in edgewise contact with the flange32 of pin 34. It will also be noted that the strip 40 has securedthereupon a contactor button 42. The contactor button 42 is nominally inengagement with a fixed contactor 43 that is supported in a threadedsleeve 44. The sleeve 44 is anchored in the top wall 19 and a likesleeve 45 is similarly disposed in axial alignment in the bottom wall20. The contactor 43 is threaded into the lower end of sleeve 44 while ascrew 46 is threaded into the outer end of the sleeve to secure the endof a wire 47 thereagainst.

A circuit from wire 47 through sleeve 44, contactors 42 and 43 and strip46 is completed through fulcrum pin 34 and by screw 48, threaded intothe tapped hole 35,'of pin 34 to the wire 49 secured thereby. If desiredsuitable washers 56 can be employed to increase the grip of the Wires 47or 49 by the screws 46 and 48.

In operation, when the plunger 38 is moved inwardly by the engagement ofa mechanically movable part such as the lug 26, the actuating member 28by reason of its magnetized body will influence the switch member 29 toswing in the opposite direction and thus separate the contactors 42 and43 momentarily or until the lug disengages from the plunger If desired,the actual motion of the member 29 can be limited by a stud 51 threadedinto the sleeve 45 and having a screw slot 52 whereby it can be turneduntil properly positioned with reference to the limit of motion ofmember 29.

In the event that it is found preferable to momentarily close anelectrical circuit through contactors 42 and 43 and wires 47 and 49, themember 29 can be bodily inverted. The contactor 43 will then replace thestud 51 in lower sleeve 45 and the screw 46 employed to attach the wire47 at the outer end thereof. Also the stud may be d threaded into theupper sleeve 44 and located to limit the motion of the switch member 29as previously described.

Now, if two control circuits are to be affected by the switch operation,the stud 51 can be removed from the sleeve 45. This will permit thetemporary closure of a second circuit while a first circuit istemporarly opened. For this purpose and as shown in Fig. 6, a contactor53 is threaded into the inner end of sleeve 45 and a screw 54 employedto secure a wire 55 at the outer end thereof. Also the strip 41 isprovided with a contactor 56. Since the strips 40 and 41 are connectedto the wire 49 through the screw 42"; and pin 34 they will now both beadapted to complete one side of an electrical circuit. The contactors42-43 will therefore maintain a circuit from wire 47 to wire 49 untilthe actuating member 28 is moved to the indicated position a of Fig. 2.Then the member 29, when swung to the position indicated at b in Fig. 2,will carry the contactor 56 on strip 41 into active and circuit closingengagement with the contactor 53. A circuit will now temporarilycompleted from wire 49 through pin 34, strip 41 and contactor 56,contactor 53 and sleeve 4-5 to screw 54 to wire 55.

Also as shown in Fig. 6, the box 16 is secured to a horizontallydisposed support plate or structural machine part 57 by screws 58 passedthrough the holes 22. When so mounted, the open side of box 16 canconveniently be closed by a plate 59, screws 60 being threaded intosleeves 23 to firmly position the said plate. This view upon comparisonwith Figs. 1 or 3, illustrates the simple yet ready adaptability of theswitch to mounting according to any of a variety of desired functionalpositions.

With reference now to Figs. 7 to 11, inclusive, there is shown a secondembodiment of my invention which is adapted to automatically operate inresponse to a change in thermal conditions. That is to say-a switch ofthe construction herein disclosed may be used to automatically controlthe heat range of ambient temperatures; it may also be mounted torespond. to the temperature of contained gases or liquids and it may,with similar adaptability, be employed as a thermostat switch in theatmosphere of gases that are known to be dangerous in the presence ofelectrical arcing.

This embodiment of the invention accordingly is adapted to control oneor more circuits by the automatic motion of permanently magnetizedelements which are substantially sealed from the atmospheres in whichthey are intended to function. Thus, the switch 61 comprises ahermetically-sealed, annularly-shaped switch receptacle or containergenerally designated by the numeral 62 that is rotatably mounted withina mounting base 63.

More particularly, the container 62 comprises an annular side wall 64and an outward or forwardly directed wall 65. The container 62 is closedby a panel or rear wall 66 on which the fixed and movable switchelements are mounted and which is sealingly secured to the peripheraledge of the side wall 64 once the switch elements have been installed.The container 62 is thus substantially hermetically sealed from theundesired entry of gases or other dangerous atmospheres.

Referring to Fig. 9, it will be seen that the switch elements include apair of fixed contacts 67 and 68 that are mounted on lugs 69 and 70integrally formed with and projecting from the inwardly disposed surfaceof the wall 66. The contacts have engagable contact points 71 and 72carried on one leg of a substantially L-shaped plate 73. The plate 73 ofeach contact is secured by its opposite leg to the respective lug 69 or70 by means of a screw 74 which also serves to fix one end of a wire 75in one case, and 76 in the other to the associated contact.

Arranged between the lugs 69 and 70, is a magnetic block 77 that ispivotally mounted on a shaft 78; the shaft being supported at its endsin suitably socketed portions of the forward wall 65 and the rear wall66. The block 77 carries a U-shaped conductive strip 79 that is equippedon each of its downwardly directed legs with contact points 81 and 82.When the block 77 is swung on the shaft78, the contact point 81 willengage the fixed contact point 71 in one direction of motion and thecontact point 82 with the contact point 71 during motion in the oppositedirection.

The contacts 67 and 68 are connected by the wires 75 and 76 to anoutside source of current. The strip 79 is also connected by a wire 83,that may be soldered or otherwise secured thereto, to the outsidecurrent source. For this purpose, the wires 75, 76 and 83 are connectedat their opposite ends to suitable clips 84, 85 and 86 that are fixedlymounted by bolts 87 that are passed through holes formed in thecontainer wall 64. To assure a firmly mounted arrangement of the bolts,the wall has an outwardly directed boss 88 integrally formed therewith.The strip 79 by the wire 83 may be connected to a source wire 89 throughthe clip 84 and associated bolt 87 and the contact 70 by wire 76 to asource wire 90 through the clip 86 and its associated bolt 87.

Here, as shown in Figs. 7 and 9, only one circuit will be controlled aswhen the contact point 82 of plate 79 is carried to engage the point 72.A circuit therefore will be established from source wire 89, wire 83,plate 79, contact point 82, contact point 72 and wire 76 to the sourcewire 90. On the other hand, two circuits may be as convenientlycontrolled by connecting a source wire to the bolt 87 associated withclip 85 and by wire 75 to the contact 69. Controllably produced swingingmotion of the block 77 on which the plate or strip 79 is mounted willaccordingly close a circuit at points 71 and 81 or points 72 and 82 ateach limit of its movement. Likewise the motion of the block, inswinging from one limit to the opposite limit as defined by the fixedpoints 71 and 72, can serve to open one circuit as between wires 75 and83 and sequentially close a second circuit between wires 76 and 83 orvice versa. 7

In order that the swinging movement of the magnetic block 77 can beautomatically and effectively carried out, a second magnetized member 91is arranged in endwise relation to the block 77. As set forth in thefirst embodiment of my invention, the blocks 77 and 91 are positioned sothat their like poles are in endwise relation to one another.Accordingly, upon motion of the block 91, the block 77 will be caused bythe repelling influence of the magnetic force to move in an oppositedirection. The block 91, if employed as the actuator, may thus be movedin response to changes in temperatures and thereby produce the openingand/or closing of an electric circuit or circuits to control. the high/or low range of a desired range of degrees of temperature.

For this purpose, the block 91 is associated with a bimetallic elementthat is situated so as to be influenced by conditions of heat or coldand, upon contracting or expanding, produce motion of the said block.More particularly, the block 91 is fixedly mounted on a shaft 92 that isjournaled at one end in the front wall 65 of the container 62.Rearwardly of the block 91, the shaft passes through the rear wall 66,the hole 93 therein affording a second journal support. The shaft 92 atits extreme end is provided with a slot 94.

In assembling the switch receptacle or container 62, the wires 75, 76and 83 are connected to their respective contacts 67 and 68 and thestrip 79 and clips 84, 85 and 86. The shafts 78 and 92 are then steppedinto their journals in the front wall 65. The shaft 92 is passed 5?through the hole 93 in the rear wall 66 after which the shaft 78 isfitted into its journal in the rear wall. This wall is then secured tothe peripheral edge of the annular wall 64 and sealed thereagainst bysuitable adhesive or other cementious material to render the containersubstantially hermetically closed.

The container is bodily received in the base 63 by engaging a flange 95depending from the annular wall 96 thereof. Preferably this flange isinterrupted to form an arcuate slot 97 while the wall 96 is providedwith a notch 98 through which the boss 88 may be passed. After properlyseating the forward wall 65 of the container against the flange 95, arear wall plate 99 is positioned so as to close the rear end of the base63 and thus enclose the container therein. For this purpose, the rearmargin of the inner surface of the wall 96 is threaded as at 100 and theperiphery of the plate 99 threaded in a like manner.

The wall 96 also carries a tubular sleeve 101 that is concentricallylocated, and attached by means of a conventional threaded connection. Inlocating the plate 99, the shaft 92 is inserted into the sleeve and theplate is then turned into the threaded portion 100 of the wall 96. Thesleeve 101 at its end adjoining the plate 99 has suitably attachedthereto one end of a coil 1020f bimetallic metals. When the plate 99 hasbeen properly located in the base 63, the free or opposite end of thecoil 102 is inserted to the slot 94 of shaft 92. Since the sleeve 101 isintended to be located in an atmosphere or liquid the temperature ofwhich is to be controlled, the extreme or open end of the sleeve ispreferably closed by a fixedly mounted and sealed plug 103.

In order to conveniently mount the base 63, the outer surface of theannular wall 96 is shaped to form a hexagonal flange or nut 104 and isthreaded as at 105. When positioned within an opening provided in a wall106, as shown in Fig. 8, and being equipped with a suitable washer 107,the base 63 can be fixedly mounted by means of a nut 108, the flange 104serving as a suitable surface to receive a wrench or other holding tool.

With the associated parts now arranged as shown in Figs. 8 and 9, itwill be seen that the distortion of the bimetallic coil 102 in responseto temperature changes will effect the rotation of shaft 92 and thusswing the magnetic block 91. As the block 91 is moved relative to theblock 77, the repulsion of their like poles will cause the block 77 toswing on its shaft 78 and produce the desired opening or closing of anelectrical circuit as above described.

Thus, if the coil 102 is adapted to expand due to an influential heatcondition, the shaft 92 will be rotated counter-clockwise, as viewed inFig. 9, and consequently the block 91 will cause the block 77 to carrythe point 82 into engagement with the point 72 of contact 70. This willcreate a circuit by wire 83 to strip 79 and contact 82 to wire 76 viacontact 70. Upon a change in temperature or decrease in the heatedcondition, the coil 102, in contracting, will move the shaft clockwisewith associated movement of the block 91 to swing the block 77oppositely and disengage the contact points 72 and 82.

Since variation of the degree of temperature at which the switch willrespond is a usual adjunct to temperature control devices, the outersurface of the flange 95 is provided with radially disposed lines 109that may be designated by suitable numerals to indicate a range oftemperature. Also the forward wall 65 of container 62 is formed toprovide a pointer 110 to register therewith. To conveniently manipulatethe container within the base 63, the outer face of wall 65 is providedwith a knob 111.

To adjust range of the operating temperature, the container 62 isrotated by the knob 111 and the boss 88 will move within the slot 97.When the. desired degree of temperature is indicated by registration ofthe pointer 110 with the properly denoted line 109, the contacts 67, 68and the magnetic block 77 will have been carried to a positionsubstantially as shown in Fig. 10. The magnetic lines of force betweenthe opposed ends of blocks 77 and 91 will accordingly be displacedandthe block 91 will not effect movement of the block 77 until by expansionof the coil 102, the block 91 has been swung to pass its proximate endpast the opposed end of block 77 and thus produce its swinging action tocarry the point 82 into engagement with the point 72 of contact 68.

It is to be understood that the forms of the invention herewith shownand described are to be taken as illustrative embodiments only of thesame, and that various changes in the shape, size and arrangement ofparts may be resorted to without departing from the spirit of theinvention or the scope of the subjoined claims.

Iclaim: f V I 1. An electric switch having a receptacle box, a pinlocated adjacent each of the opposite ends of said box, each pin havinga body portion supported in a wall of the said box, and an integral axleportion of reduced diameter projecting inwardly therefrom, a switchoperating member including a magnetic block pivotally mounted at one ofits ends on. the axle portion of one of said pins, a strip of conductivemetal afiixed to one side of the magnetic block in surface contact withthe body portion of the said pin, means connecting said first pin to oneside of an electric circuit, a second electric circuit source mounted ina second wall of the box and adapted to be engaged by the free end ofthe switch operating member, a switch actuating member including amagnetic block pivotally mounted at one of its ends on the axle portionof the second of said pins and disposed in alignment with the magneticblock of the switch operating member, resilient means .engageable withthe switch actuating member for normally urging it into a position tohold the conductive strip of said switch operating member in engagementwith the said second circuit source during repulsion of magnetic forcesbetween the magnetic blocks of the said switch actuating and switchoperating members, separate control means operable to cause said switchactuating member to move against the normal action of the resilientmeans whereby said switch operating member is moved from a circuitclosed to a circuit open position, and means limiting movement of thesaid switch operating member from a circuit closed position.

2. An electric switch as'defined in claim 1, wherein said resilientmeans includes a coil spring for automatically reversing the repulsingaction of the switch actuating member upon release of the said separatecontrol means.

3.. Anelectric switch as defined in claim 1, wherein said separatecontrol means includes a pin slidably supported in a wall of thereceptacle box inopposition to said resilient means.

An electric switch as defined in claim 1, wherein said limiting meansincludes a threadably mounted member positioned in a wall of thereceptacle box and adapted to adjustably limit the pivotal movement ofthe switch. operating member between the circuit closed and circuit openpositions.

References Cited in the file of this patent UNITED STATES PATENTS Re.21,038 Leins Mar. 28, 1939 1,975,856 McCabe Oct. 9, 1934 1,976,954 MantzOct. 16, 1934 2,012,153 Bates Aug. 20, 1935 2,520,935 Hubbell Sept. 5,1950 2,529,652 Dicks Nov. 14, 1950 2,671,834 Kmiecik Mar. 9, 19542,718,569 Johnston Sept. 20, 1955 2,725,439 Newboult Nov. 29, 1955FOREIGN PATENTS 118,575 Australia June 15, 1944 567,982 France Dec. 14,1923

